1. Field of the Invention
This invention relates to an apparatus for continuously measuring the flatness, that is, the verticality and flatness and thickness in a suspended state, of electrode plates such as anodes or cathodes for electrolysis used in the electrolytic refining of copper or nickel or the like.
2. Description of the Prior Art
The method generally used in the electrolytic refining of for example copper is to so suspend a starting copper anode and a starting copper cathode in an electrolytic cell that they face each other at a fixed distance apart, the so called pitch between electrodes. It is important that the suspended anode and cathode be a fixed distance apart over the entirety of their facing surfaces, and when either of the electrode plates is deformed or is of nonuniform thickness, abnormal electrodeposition occurs where the inter-electrode is short, and in extreme cases the anode and the cathode short-circuit. This kind of abnormal electrodeposition results in poor electrolytic copper quality, and at this time the electrical current efficiency is reduced by short-circuiting. For this reason it is required that the anodes and cathodes have good flatness and be of uniform thickness in their suspended state in the electrolytic cell.
There is not yet any means by which the flatness and thickness of this kind of electrode plate can be measured industrially, and at present the only correction being performed is that of a warp great enough to be visually discerned. An apparatus for measuring cathode warp using a non-contact sensor is disclosed in for example, Japanese Laid-Open Utility Model Publication No. S.64-33607, but because in this apparatus a single sensor is swept over the electrode plate and the distance between the electrode plate surface and the sensor is measured, the measuring time is long and consequently handling numerous electrode plates is in practice problematic and furthermore there is the shortcoming that there is no provision for measuring the thickness of the electrode plate.